EFFECT OF COMBINED APPLICATION OF BIOFERTILIZER AND NITROGENOUS FERTILIZER ON GROWTH AND YIELD OF WHEAT (Triticum aestivum L.)

Abstract

The experiment was conducted at the research field, Sher-e-Bangla Agricultural University during the period from November, 2019 to March, 2020 to study the effect of combined application of biofertilizer and nitrogenous fertilizer on growth and yield of wheat (Triticum aestivum L.). The experiment comprised of single factor comprising eight treatments. Azotobacter was incorporated with wheat seed as per treatment. This experiment was laid out in a randomized complete block design (RCBD) with three (3) replications. The results revealed that treatment T₅ [Azotobacter (4 kg ha⁻¹) + 90 kg N ha⁻¹] exhibited its superiority compared to that of other biofertilizer and nitrogenous fertilizer treatments in terms of grain yield. Treatment T₅ out-yielded over T₈ (No Azotobacter + 120 kg N ha⁻¹) by 5.26%, T₃ [Azotobacter (6 kg ha⁻¹) + 60 kg N ha⁻¹] by 7.57%, T₆ [No Azotobacter + 90 kg N ha⁻¹] by 8.64%, T₇ [Azotobacter + 120 kg N ha⁻¹] by 13.69%, T₄ [No Azotobacter + 60 kg N ha⁻¹] by 15.18% and T₂ [Azotobacter (8 kg ha⁻¹)] by 25.00% higher grain yield. Treatment T₅ also showed the tallest plant at 90 DAS (107.53 cm), the highest number of spikelets per spike (19.47), the highest number of grains per spike (75.93), the longest spike (15.70 cm), the maximum weight of 1000grain (48.90 g),

the highest straw yield (7.68 t ha⁻¹) and the maximum harvest index (38.76%) than other treatments in this experiment. On the other hand, the treatment T₁ [Control (No Azotobacter, No N as urea)] returned with 69.88% lower yield than treatment T₅ which was significantly the lowest compared with other treatments under study. In case of soil properties, the highest soil pH (6.21) and the highest soil organic matter (1.58%) in post-harvest soil was recorded from the treatment T₅ [Azotobacter (4 kg ha⁻¹) + 90 kg N ha⁻¹]. Considering the soil nutrients, the maximum total N (0.11%), the maximum available phosphorous (25.96 ppm), the maximum available sulphur (20.73 ppm) and the highest exchangeable K (0.129 me%) in post-harvest soil was recorded from the treatment T₅ [Azotobacter (4 kg ha⁻¹) + 90 kg N ha⁻¹]. It can be said that Azotobacter along with nitrogenous fertilizer improved soil chemical properties along with increased availability of essential plant nutrients in soil solution. Azotobacter (4 kg ha⁻¹) + 90 kg N ha⁻¹ application seemed promising for producing higher grain yield of wheat and sustaining soil productivity.